JPH0358852B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to electrical discharge machines, and more particularly to an apparatus for angular indexing of a tool holder.

[Background Art] The following device is known as an electrical discharge machine that rotates a tool holder. That is, an apparatus is known in which a spindle is rotatably supported on a body, a tool holder is detachably held on the spindle, and the spindle is rotated by a servo motor or the like.

In order to improve machining accuracy or machining a variety of shapes, it is conceivable to add an angle indexing device to the conventional device described above, but as a premise, it is necessary to detect the origin position of the tool holder. be.

As the tool holder origin position detection device, it is conceivable to fix a magnet at a predetermined position on the tool holder and provide a reed switch at a predetermined position on the body. By doing this, when the magnet of the tool holder faces the reed switch of the body while the tool holder is being rotated in any direction, the reed switch is activated and the origin position of the tool holder is determined at this time. can be detected. After that, the angle of the tool holder is determined.

[Problem to be Solved by the Invention] In the above-mentioned prior example, in order to detect the origin position, magnets must be provided for all tool holders, so there is a problem that the magnet installation is complicated. .

In order to detect the origin position of the tool holder, in addition to the combination of a magnet and a reed switch, other position detection sensors such as an optical sensor are used. Therefore,
Generally speaking, the above example has a problem in that it is complicated to install position detection sensors on all of the tool holders.

Further, even if the origin position is electrically detected, for example, the error may be large, and there is also the problem that it is impossible to meet the demand for reducing the error to zero as much as possible.

[Means for Solving the Problems] The present invention includes a tool holder pin having a predetermined taper that interlocks with a tool holder, and two protrusions provided at a predetermined interval in the circumferential direction at the lower part of the spindle. , a slidable wedge that is placed along one of the protrusions and clamps the tool holder pin between the other protrusion and positions the tool holder with respect to the spindle; and the tool holder. The device has a V-groove in a portion facing the pin, is provided on the body and is movable in the radial direction of the spindle, and has a position detection sensor provided between the spindle and the body. By pressing the tool holder interlocking pin against the end surface of the other protrusion, the wedge determines the position of the tool holder with respect to the spindle and transmits rotational force to the tool holder.

[Function] The present invention has a V-groove in a portion facing the tool holder pin, and a holding means that is movable in the radial direction of the spindle is provided in the body, and a wedge holds the tool holder interlocking pin on the end surface of the other protrusion. Since the tool holder is pressed against the spindle, the position of the tool holder relative to the spindle can be determined reliably, and rotational force can be reliably transmitted to the tool holder.

[Embodiment of the invention] FIG. 1 is an explanatory diagram of an embodiment of the present invention,
FIG. 2 shows the tool holder 40 in the above embodiment.
Fig. 3 is a front sectional view of the case where the
FIG. 3 is a partially cutaway bottom view of FIG. 2;

A reed switch 10s is placed in a predetermined position on the body 10.
A bearing holding ring 11 is provided at the lower part of the body 10, and a spindle 20 is rotatably supported by a bearing on the body 10.
The spindle 20 has a diaphragm 21, a chuck 22, and a chuck 22 that transmits the vertical force of the diaphragm 21 to the chuck 22.
An opening/closing rod 23 for opening and closing 2 is provided. Further, an air suction port 24 is provided above the spindle 20, and an air intake port 24 is provided below the spindle 20.
A tapered hole 25 is provided.

Note that a magnet 20s is placed at a predetermined position on the spindle 20.
is provided, and this magnet 20s is attached to the spindle 20
By determining the position of the spindle 20 with respect to the body 10 while rotating the body 10
This is to determine the position of the tool holder 40 with respect to.

Interlocking means are provided for interlocking the tool holder 40 and the spindle 20. This interlocking means is composed of a tool holder pin 44 provided on the tool holder 40 and a clamping means 30. This clamping means 30, as shown in FIG.
The spindle 20 is linked with the spindle 20.
It is provided at the lower part of the tool holder pin 44 at a position where the tool holder pin 44 is clamped therebetween. Here, FIG. 4 is a right side view of FIG. 2 with the clamping means 80 omitted, and FIG. 5 shows the case of FIG. 4 without the tool holder 40 attached. It shows the case.

That is, the clamping means 30 is composed of two protrusions 31 and 32 provided at a predetermined interval in the circumferential direction at the lower part of the spindle 20, and a slidable wedge 33 along the protrusion 31. ing. Of course, wedge 3
3 may be made to slide along the protrusion 32. That is, the wedge 33 has a degree of freedom in the vertical direction in the figure.

Note that reference numeral 34 is a spring that slides the wedge 33 along the protrusion 31 and biases the wedge 33 downward. Reference numeral 35 is the left side surface of the protrusion 32.

In FIG. 1, the tool holder 40 has an outer surface taper 41 on its upper part, and this outer surface taper 41
This fits into the tapered hole 25 of the spindle 20.

Note that a tool (not shown) is provided under the tool holder 40, but this tool is a die for electrical discharge machining, a cutting tool for cutting, and various other commonly thoughtable tools. Tools are applicable.

In FIG. 1, a speed control motor 50 rotates the spindle 20 in order to detect the origin position of the tool holder 40. As shown in FIG. Further, a reduction gear device 51, a servo motor 52, and an encoder 53 are provided coaxially with the spindle 20 via a clutch 54. Servo motor 52
is for rotating the spindle 20 during electrical discharge machining, the reduction gear device 51 is for reducing the rotation speed of the servo motor 52, and the encoder 5 is for reducing the rotation speed of the servo motor 52.
3 detects the rotation angle when indexing the angle of the tool holder 40 after detecting the origin position of the tool holder 40. In addition, code 5
5 indicates a brake.

The tool holder attachment/detachment nozzle 61 has its tip joined to the air suction port 24 of the spindle 20.
By supplying air, the chuck 22 is opened and the tool holder 40 is attached and detached. Note that the reference numeral 62 is a limit switch.

Further, a required pulse voltage is supplied to the spindle 20 via the interpolar wire 71 and brushes 72 and 73.

Furthermore, a clamping means 80 is provided at the bottom of the bearing ring 11.
is provided. This clamping means 80 clamps the outer surface taper 44t of the taper pin 44 provided on the tool holder 40. This clamping means 80
A cross-sectional view of is shown in FIGS. 2 and 3. A solenoid 81 is provided in the case, and a plunger 82 that is movable forward and backward in the radial direction of the spindle 20 is provided in the center of the solenoid 81 .

The plunger 82 can move forward and backward in the radial direction of the spindle 20. In other words, plunger 8
2 is always biased in the radial direction of the spindle 20 (to the right in the figure) by a spring 83, and is sent to the axis of the spindle 20 (to the left in the figure) when the solenoid 81 is excited. It is. 2nd, 3rd
The figure shows a state in which the plunger 82 is retracted. Further, the tip of the plunger 82 has a V-groove 8
4 is formed, and this V groove 84 is connected to the taper pin 44.
This is the part that fits with the outer surface taper 44t.

Next, the operation of the above embodiment will be explained.

First, as shown in FIG.
Assume that it is not installed. In this case, nozzle 6
1 is applied to the air suction port 24 to supply air, the chuck 22 is opened, the tool holder 40 is inserted from below the spindle 20, and the nozzle 61 is pulled away, so the chuck 22 closes and the tool holder 40 is opened as shown in the figure. , never fall.

In addition, as shown in FIG. 4, in the position where the tool holder pin 44 pushes up the wedge 33, the tool holder pin 44 touches the slope 36 of the wedge 33 and the side surface 33.
5 and fixed in the state shown in the figure, the tool holder 40 has no play in the circumferential direction with respect to the spindle 20. In this case, it is assumed that the origin position of the tool holder 40 has not yet been detected.

Here, the origin position of the tool holder 40 is a position where the tool holder 40 needs to be oriented in a predetermined direction when indexing the angle of the tool holder 40.

Then, when the speed control motor 50 starts rotating, the tool holder 40 rotates together with the spindle 20, and the magnet 20s provided on the spindle 20 also rotates, gradually approaching the reed switch 10s, and the magnet 20s moves toward the reed switch. 10
s, the reed switch 10s outputs an output. Based on this output, it is tentatively determined that the tool holder 40 is at the origin position.

However, due to the accuracy of the reed switch 10s,
There are cases where the origin position is not reliably detected. Taking this case into consideration, forced positioning is performed using the clamping means 80. In other words, the second
From the state shown in FIG. 3, the solenoid 81 is energized. As a result, the plunger 82 advances toward the taper pin 44, and the outer taper 44t of the taper pin 44 comes into contact with the V-groove 84 of the plunger 82.
4 as a guide, the taper pin 44, that is, the tool holder 40, is accurately moved to the original position. When positioning is forcibly performed by the clamping means 80 as described above, it is necessary to disengage the clutch 54. After this forced positioning is completed, the clutch 54 is connected.

In this manner, the speed control motor 50 is stopped when the origin position of the tool holder 40 is accurately detected. And solenoid 81
The plunger 82 is retracted to the position shown in FIGS. 2 and 3.

Then, the angle of the tool holder 40 is determined from that position. Thereafter, during electrical discharge machining, the tool holder 40 is rotated by a predetermined angle as required by the servo motor 52 and the reduction gear device 51.
As a result, workpieces (not shown) are processed into various shapes.

In the above embodiment, when detecting the origin position of the tool holder 40, there is no need to provide a magnet for each tool holder 40, and the origin position detection device has the advantage of being easy to manufacture.
Furthermore, the clamping means 80 has the advantage that the origin position can be detected more accurately.

FIG. 6 is a diagram showing another embodiment of the present invention, and corresponds to the right side view (FIG. 4) of FIG. 2. However, in FIG. 6, the main body of the tool holder 40 and the clamping means 80 are omitted, and only the tool holder pin 44 is shown. In the embodiment shown in FIG. 6, when compared with FIG. 4, the wedge 33a is slidable in the lower right direction. Further, when the wedge 33a presses the tool holder pin 44, the pressing surface thereof is parallel to the right side surface 35a of the protrusion 32a, that is, it has a perpendicular surface. For this purpose, the sixth
The illustrated embodiment has the advantage that the tool holder pin 44 can be clamped securely.

In addition, the reference numeral 20a is a spindle, the reference numeral 31a is a protrusion that clamps the tool holder pin 44 together with the protrusion 33a, and the reference numeral 34a is a spring.

In the above embodiment, a magnet and a reed switch are provided as position detection sensors, but other position detection sensors such as a photo sensor, a limit switch, a proximity switch, etc. may be used instead of these. Further, instead of the combination of the servo motor 52 and the speed reducer 51, a pulse motor may be used. Moreover, the tool holder 40 and the spindle 20 may be interlocked by other means other than the clamping means 30. A cutting tool may be used as the tool for cutting, that is, the workpiece may be roughly cut, and then finished by electrical discharge machining.

Note that a liquid actuated device may be used to move the plunger 82 forward and backward.

[Effects of the Invention] According to the present invention, the tool holder can be accurately positioned with respect to the spindle, and rotational force can be reliably transmitted to the tool holder.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of an embodiment of the present invention, Fig. 2 is a sectional view showing the tool holder attached to the spindle, Fig. 3 is a bottom view of Fig. 2, and Fig. 4 omits the clamping means. The right side view of Figure 2, Figure 5 is the 4th side view.
The figure shows a state in which the tool holder is not attached, and FIG. 6 is a right side view showing another embodiment of the present invention. 10...Body, 10s...Reed switch, 20
... Spindle, 20s... Magnet, 30, 30a... Clamping means, 31, 31a, 32, 32a... Protrusion, 3
3, 33a... Wedge, 40... Tool holder, 44... Taper pin, 44T... External taper, 50... Speed control motor, 51... Reduction device, 52... Servo motor, 53... Encoder, 80... Clamping means, 81... Solenoid, 82 …Plungeer, 84
...V groove.

Claims (1)

[Scope of Claims] 1. An angle indexing device for a tool holder for an electric discharge machine, in which a spindle is rotatably supported with respect to a body, and a rotating means rotates the tool holder by a predetermined angle via the spindle, comprising: A tool holder that interlocks with the tool holder and has a predetermined taper; Two protrusions provided at the lower part of the spindle at a predetermined interval in the circumferential direction; One of the protrusions; a slidable wedge for positioning the tool holder with respect to the spindle by aligning the tool holder interlocking pin with the other protrusion; and having a V-groove in a portion facing the tool holder pin; , a clamping means provided on a body and movable in a radial direction of the spindle; a position detection sensor provided between the spindle and the body; and the wedge is connected to the tool holder interlocking pin. By pressing the above against the end face of the other protrusion,
A tool holder angle indexing device for an electrical discharge machine, characterized in that the device determines the position of the tool holder with respect to the spindle and transmits rotational force to the tool holder. 2. The angle indexing device for a tool holder for an electrical discharge machine according to claim 1, wherein the position detection sensor is a magnetic sensor, a photo sensor, a reed switch, or a proximity sensor.